Chinon A2, one of six gas-cooled reactors (Uranium Naturel Graphite Gaz, or UNGG) in France, is a key focus of 
EDF's immediate dismantling strategy. These six reactors, located at Bugey, Chinon, and St Laurent-des-Eaux, entered service between 1963 and 1972. Chinon A2 is designated as the lead site for this strategy, with the goal of dismantling facilities in the shortest possible timeframe.
A decisive milestone has been reached with the validation of the contractual strategy for dismantling Chinon A2's heat exchangers. This follows over three and a half years of joint studies by teams from EDF's Deconstruction and Waste Projects Department (DP2D) and Cyclife Engineering. This validation enables the launch of the first operational phase for dismantling the world's first UNGG reactor.
The initial operation, pending the entry into force of the dismantling decree, will involve the systematic dismantling of equipment within the four heat exchanger rooms of Chinon A2. These heat exchangers were crucial for transferring heat from carbon dioxide, heated in the reactor core, to the water of the secondary circuit, which then produced steam. The project is expected to take six years, with operations slated to begin in mid-2028, following a public inquiry into the UNGG reactor dismantling strategy scheduled for 2027.
Lessons learned from the dismantling of Chinon A3 reactor heat exchangers are expected to benefit this operation. Stéphanie Proust, EDF Chinon A-AMI project manager, highlighted the significance of this step in preparing for an industrial project that will serve as a benchmark for EDF's entire UNGG program.
In December 2019, EDF and Veolia established Graphitech, a joint venture focused on decommissioning graphite technology reactors. Graphitech's initial objective was to provide EDF with an optimized decommissioning scenario for the Chinon A2 reactor by 2028 and to develop a testing program for evaluating necessary technological solutions. This program commenced in 2022 with a development and qualification phase, utilizing full-scale models to prepare remote-operation tools for the Chinon reactor's decommissioning. Graphitech has also outlined a decommissioning methodology for the remaining five UNGG reactors, aiming to transpose the Chinon A2 methodology where feasible, and identifying additional engineering work where necessary. Graphitech plans to pursue contracts for assisting in the dismantling of gas-cooled reactors in various countries, including France, Italy, Japan, Lithuania, Spain, and the UK.
